GENEVA, Dec. 5, 2008 — Repairing the giant particle collider built to simulate the "Big Bang" could cost up to $29 million, Europe's CERN nuclear research center said Friday.

Announcing a further delay to the Large Hadron Collider's restart, now expected in summer, CERN spokesman James Gillies said the repairs would cost $12.5 million, and spare parts would cost another $8.25 million to $16.5 million.

The massive collider, the largest and most complex machine ever made, has already cost about $10 billion to build, supported by CERN's 20 European member states and other nations including the United States and Russia.

"We will not be going to our member states asking for more money, we will deal with it within the current CERN budget," Gillies said.

The collider is designed to re-create the conditions that existed just after the Big Bang, believed by most cosmologists to have created the universe 13.7 billion years ago. Experiments planned at the facility could shed new light on mysteries ranging from the nature of dark matter and black holes to the possible existence of as-yet-undetected dimensions in the universe.

The machine sends beams of sub-atomic particles to smash into each other at nearly the speed of light. Physicists plan to look at the results of those explosions for new or previously unseen particles.

Scientists started up the LHC with great fanfare in September, firing beams of proton particles all the way around its 17-mile (27-kilometer) underground tunnel. But nine days later they were forced to shut it down when an electrical fault caused a helium leak.

Gillies said that helium leak caused "quite considerable mechanical damage to the accelerator."

Repairing it will require 53 of the 57 magnets in the collider's tunnel, buried under the Swiss-French border near Geneva, to be removed and then reinstalled.

Some 28 have already come out, and all the magnets should be back in place by the end of March, Gillies said. CERN now expects the machine to be powered up again for tests by June, after which particle beams can be sent around again.

"We don't have a precise date for it yet," the spokesman said. Even after the machine is restarted, it will take additional time to ramp up the energy in the beams to their full strength.